Descending perineum syndrome (DPS)

Descending perineum syndrome (DPS) is a common pelvic floor condition affecting women, causing constipation. Descending perineum syndrome can be difficult to manage, with diagnosis consisting of high suspicion combined with a physical examination and imaging.

Management of descending perineum syndrome includes bowel regimens, with surgery not usually part of treatments. Descending perineum syndrome is an increased bulging of the perineum when straining to have a bowel motion, and in some cases can be seen when at rest.

Women who are chronically constipated and often strain to defecate are prone to this condition. It is understood to be a result of obstructed defecation, however is uncommonly diagnosed and not always easy to treat.

DPS may coexist with rectocele, intestine disorders (intussusception), or rectal prolapse. DPS may appear with vaginal symptoms such as a bulge or heaviness, and urinary symptoms such as urinary incontinence, urgency, hesitancy, and a feeling of incomplete emptying.

Factors associated with descending perineum syndrome are ageing, the number of vaginal deliveries, and obesity. The ultimate result ends up the same: impaired supportive connective tissue of the pelvis and pelvic floor dysfunction.

Normal and abnormal perineal descent

Determining what is normal and abnormal when examining the perineal area varies from person to person, with some overlap seen in studies. Early studies of women without bowel symptoms demonstrated that 77 per cent had a measured perineal descent of less than 3cm, while another study found that 84 per cent of women had perineal descent of less than 2cm, with normal ranges going up to 4.4cm of descent.

Descent between 3-4cm and straining values from 2.5-4cm have been discussed as being abnormal and may suggest descending perineum syndrome. With such a wide variety of values noted in previous studies on DPS, diagnosis can be challenging.

Symptoms of descending perineum syndrome

• History of chronic straining during bowel motions
• Sensation of incomplete evacuation
• Sensation of obstruction follows
• Mucous discharge out of anus
• Rectal or anal bleeding
• Anal irritation
• Chronic anal pain
• Itching anus
• Faecal incontinence and leakage
• Anal/rectal prolapse

How descending perineum syndrome occurs

Chronic and repetitive straining of the pelvic floors, weakening the muscles, can occur with constipation. The perineum balloons out, with the rectum entering into the anal canal and protruding outwards. It is this that causes the feeling of incomplete evacuation, which causes further straining.

This excessive straining results in the prolapse of the rectum wall, which causes the other symptoms of mucous discharge, bleeding and itching. This may result in the pudendal nerve being irritated and stretched, causing chronic pain and permanent damage. 

It is unclear whether stretching of the pudendal nerve causes anal incontinence – sometimes it seems to be related, while other times not. DPS affects the whole pelvic floor, with excessive, chronic straining – pressure – weakening the entire pelvic floor over time, allowing the descent of tissues.

The pelvic floor becomes funnel-shaped after the puborectalis muscle is stretched. Reflexes are impaired, in particular the post-defecation reflex – that is, a sharp contraction of the levator ani muscles that reposition the pelvic floor after it sinks down to allow a bowel motion.

The stretching of the pelvic floor muscles when straining impairs the reflexive contraction of the pelvic floor, and the whole system of muscles and ligaments becomes stretched and loose. The muscles stop returning to their original position. This is how the perineum descends.

This is the same sort of anatomical arrangement found in women with pelvic organ prolapse (POP) and DPS is a risk factor for further prolapse.

Under imaging, DPS can look like POP.  DPS can be exacerbated by low pelvic floor tone, age, uterine surgery, and other elements. Over time, faecal incontinence may appear due to denervation and weakness of the external anal sphincter muscle.

Faecal incontinence is considered a late-stage symptom. Rectal prolapse may appear next.

Treating descending perineum syndrome

Treatment for DPS should be conservative – DPS does not typically require surgery, which has tended to make things worse. Modifications of bowel habits is in order to try to help repair tissue, and the original cause of constipation needs addressing.

Treatment is tailored to the individual and stage their DPS is at. If appropriate, diet changes to alleviate constipation will be recommended, and the DPS may heal by itself if it is not severe.

Strengthening and modifying the pelvic floor will also be considered, since it is ultimately a pelvic floor disturbance with a clear cause.

Rehabilitation of the pelvic floor using biofeedback and pelvic-perineal kinesitherapy (a type of muscular training for the levator ani muscles) is often a first-line option in some women who are early in DPS.

Biofeedback conditions the defecation reflex by pelvic floor strengthening training exercises and visual/verbal feedback training. Rehabilitation tends to have good outcomes, with symptoms improving significantly. How well you respond is determined largely by how far your perineum has descended when you start receiving treatments.

Those with over 4.9cm of descent don’t respond as well to these treatments, however women with around 3 cm of descent respond very well. 

Rehabilitation can help with faecal incontinence too, but some women do not respond at all. In this case, surgery may be an option. Rehabilitation is aimed squarely at improving pelvic floor function.

Who you see for this pelvic physiotherapy will differ depending on where you live, but a pelvic physiotherapist is usually recommended.

References

• Chaudhry, Z., & Tarnay, C. (2016). Descending perineum syndrome: A review of the presentation, diagnosis, and management. International Urogynecology Journal, 27(8), 1149-1156.
• Pucciani, F. Tech Coloproctol (2015). Descending perineum syndrome: new perspectives, 19: 443. Techniques in Coloproctology August 2015, Volume 19, Issue 8, pp 443–448